Crash in CBForest querying a view while device is locked

[snej]

A developer reports errors including crashes when querying a view while the device is locked — apparently the filesystem access isn't allowing the view file to be opened. Definitely shouldn't be a crash!

[FDB ERR] Error in OPEN on a database file '/var/mobile/Containers/Data/Application/536281B4-4C4A-4C8A-8C37-8A055E99ECEA/Library/Application Support/CouchbaseLite/cbase.cblite2/Device.viewindex.0', errno = 1: 'Operation not permitted'
2016-08-29 14:16:21.706 Org APP[9923:3497076] WARNING: ForestDB error: A file operation is not permitted (-50)
{at FDBLogCallback:68}

* thread #1: tid = 0x355c74, 0x000000018275411c libsystem_kernel.dylib`__pthread_kill + 8, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
frame #0: 0x000000018275411c libsystem_kernel.dylib`__pthread_kill + 8
frame #1: 0x0000000182820ef8 libsystem_pthread.dylib`pthread_kill + 112
frame #2: 0x00000001826c5dc8 libsystem_c.dylib`abort + 140
frame #3: 0x00000001821f93f4 libc++abi.dylib`abort_message + 132
frame #4: 0x0000000182215e80 libc++abi.dylib`default_terminate_handler() + 280
frame #5: 0x0000000182220264 libobjc.A.dylib`_objc_terminate() + 152
frame #6: 0x0000000182220264 libobjc.A.dylib`_objc_terminate() + 152
frame #7: 0x0000000182212f44 libc++abi.dylib`std::__terminate(void (*)()) + 16
frame #8: 0x0000000182212fd0 libc++abi.dylib`std::terminate() + 92
frame #9: 0x00000001007658cc OrgCore`__clang_call_terminate + 16
frame #10: 0x0000000100796ee4 OrgCore`c4View::c4View(c4Database*, cbforest::slice, cbforest::slice, fdb_config const&, cbforest::slice) [inlined] c4Internal::RefCounted<c4View>::~RefCounted() + 432 at c4Impl.hh:116
frame #11: 0x0000000100796e7c OrgCore`c4View::c4View(this=0x0000000115f5fe48, sourceDB=<unavailable>, path=<unavailable>, name=<unavailable>, config=<unavailable>, version=<unavailable>) + 328 at c4View.cc:56
frame #12: 0x0000000100795034 OrgCore`::c4view_open(C4Database *, C4Slice, C4Slice, C4Slice, C4DatabaseFlags, const C4EncryptionKey *, C4Error *) [inlined] c4View::c4View(this=<unavailable>, sourceDB=<unavailable>, config=<unavailable>) + 156 at c4View.cc:54
frame #13: 0x0000000100795010 OrgCore`::c4view_open(db=<unavailable>, path=<unavailable>, viewName=<unavailable>, version=<unavailable>, flags=<unavailable>, key=0x0000000000000000, outError=0x0000000000000006) + 120 at c4View.cc:102
frame #14: 0x000000010076c460 OrgCore`-[CBL_ForestDBViewStorage openIndexWithOptions:status:](self=0x0000000125ec83b0, _cmd=<unavailable>, flags=<unavailable>, outStatus=0x0000000000000000) + 368 at CBL_ForestDBViewStorage.mm:181
frame #15: 0x000000010076c248 OrgCore`-[CBL_ForestDBViewStorage lastSequenceIndexed](self=0x0000000125ec83b0, _cmd=<unavailable>) + 32 at CBL_ForestDBViewStorage.mm:132
frame #16: 0x000000010082f3b0 OrgCore`-[CBLDatabase(self=0x0000000125e8b4f0, _cmd=<unavailable>, viewName=<unavailable>, options=<unavailable>, ifChangedSince=-1, outStatus=0x000000016fdd95ac) queryViewNamed:options:ifChangedSince:status:] + 124 at CBLQuery.m:485
frame #17: 0x000000010082dda8 OrgCore`-[CBLQuery run:](self=0x0000000125dc9550, _cmd=<unavailable>, outError=domain: class name = CBLQuery - code: 0) + 152 at CBLQuery.m:219
frame #18: 0x00000001006f351c OrgCore`(view="Device", descending=true, startKey=nil, endKey=nil, limit=0, database=0x0000000125e8b4f0, self=0x0000000125da52d0).query(String, descending : Bool, startKey : AnyObject?, endKey : AnyObject?, limit : UInt, database : CBLDatabase) -> [DatastoreModel]? + 676 at Datastore.swift:189
frame #19: 0x00000001006f2acc OrgCore`Datastore.query(view=DeviceModel, database=nil, self=0x0000000125e85d20) -> [DatastoreModel]? + 360 at Datastore.swift:135
frame #20: 0x000000010014c558 Org APP`HomeAPPGraphViewModel.(self=0x0000000125ede180).getter + 72 at HomeAPPGraphViewModel.swift:125
frame #21: 0x00000001001497c8 Org APP`HomeAPPGraphViewModel.(heartRate=71, todayDailySummary=0x0000000125d88180, self=0x0000000125ede180)(Int?, DailySummaryModel?) -> [String : AnyObject]? + 440 at HomeAPPGraphViewModel.swift:80
frame #22: 0x000000010014a1c0 Org APP`HomeAPPGraphViewModel.(oldValue=70, self=0x0000000125ede180).didset + 236 at HomeAPPGraphViewModel.swift:37
frame #23: 0x000000010014a46c Org APP`HomeAPPGraphViewModel.(newValue=71, self=0x0000000125ede180).setter + 76 at HomeAPPGraphViewModel.swift:0
frame #24: 0x000000010014e694 Org APP`HomeAPPGraphViewModel.(event=(Next = 71)

[basememara]

Duplicate but critical: #1422

[pasin]

Closed as dup.